Front head for percussive drills



1 632 921 June 1927' E. PENBERTHY FRONT HEAD FOR PERCUSSIVE DRILLS Filed S 5Y1; A TTOANE) Patented 'June 21, 1921.

UNITED STATES 1,632,921 PATENT OFFICE.

ERNEST PENBERTHY, OF DETROIT, MICHIGAN, A SSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEW YORK, N. Y., A. CORPORATION OF NEW JERSEY.

FRONT HEAD FOR PERCUSSIVE DRILLS.

Application filed September 80, 1924. Serial No. 740,755.

This invention relates to percussive machines of the type used in mining and drilling operations. More particularly it relates to the front head construction of such machines intended especially but by no means exclusively for use-in stoping.

Heretofore it has been the practice to use different front heads for stopers, one head for wet drilling and another for dry drilling, the latter being usually provided with drain holes to permit the dust and grit which finds its way into the head to drop out. With the present tendency toward the universal type of drill (readily adaptable to either wet or dry drilling), these prior forms of front heads require the operator to equip each drill with a duplicate set of front heads and to change each time he changes his method of drilling, as from dry to wet or vice versa. Moreover the type of front head with drain holes is objectionable I in that it permits dust and grit to follow the steel into the chuck resulting in rapid wear and in addition this powdered abrasive material issues from the drain holes in close proximity to the drilling machine where it is liable to find its way'within the machine itself to continue its rapid and destructive work.

Among the objects of the invention are to provide a type of front head construction adapted without change to both wet and dry drilling, to eliminate to a great extent the wear of parts in the front head including the chuck by preventing the entrance of detritus from the drilling operation, to insure rbtation of the drill steel when the drilling machine is rotated, to permit the use of interchangeable'chuck bushings of different sizes and shapes without impairing the rotative connection between the drilling machine and the drill steel, and in general to improve prior devices 'of this character in the interests of more economical, more efficient and more satisfactory service.

The invention comprises a front head construction without transverse openings having its interior supplied with motive fluid in limited amount which fluid passes along the chuck to keep out the dust, grit, or mud. This stream of motive fluid may also be utilized to convey lubricant to the bearing surfaces in the front head. Rotation of the drill bit with the drilling machine is insured by keying the hit chuck to the machine. A

preferred construction for this pur se comprises interlocking portions on t e chuck bushing and the drilling machine or some relative rotative Fig. 1 is a longitudinal sectional viewof onefo'rm of the invention taken substantially on the broken line 1-1 of Fig. 2;

Fig. 2 is a sectional view on the line 2-2 of Fig. 1;

Fig. 3 is a longitudinal sectional view similar to Fig. 1 of a modification taken irubstaintially on the broken line 3-3 of Fig. 4 is a sectional view on the line 4-4 of Fig. 3 showing the impact and bearing members in elevation;

Fig. 5 is a diagrammatical showing in 1 elevation of certain details of the form of the invention shown in Figs. 3 and 4.

In the embodiments of the invention illustrated in Figs. 1 to 4 inclusive, a ortion only of a percussion machine is disclosed with the parts comprising the invention secured thereto. While the percussive ma.- chine may be of any well lmown or desired type, the one partly disclosed in the drawings is operated by pressure fluid, such as compressed air. I

Referring now to Figs. 1 and 2 the cylinder 6 of the percussive machine has a front head '7 secured thereto by any suitable or desired means such as bolts 8 extending through erforated ears or 'lugs 9 and 10 on the rill cylinder and head respectively, the pro'ecting portions of the bolts being encircle by shock absorbing springs 11 backed by suit able retaining nuts 12 and lock washers 13. The front head 7 serves as a chuck and re ceives the rear end of the shank of the working steel, drill steel, or hit 14 disposing the latter in position to receive the blows of the impact member 15 of the percussive machine which may form a part of or be independent of the reciprocating piston or hammer 16. The impact member '15 is mounted for limited reciprocatory movement in a bear= ing or guide member 17 end of the cylinder 6 and pre erably interposed as shown between the cylinder 6 and the front head 7, grooves 18 being provided parti closing the END in member 17 to receive the connecting bolts and to secure the member against rotative movement relative to the drilhng machine.

To prevent dust and grit in dry drilling or mud in wet drilling from working into the front head 7 along and around the drill steel 14, a continuous flow of motive fluid in limited amount is directed into the front head. For this urpose a motive fluid passage 19 in the dril cylinder terminates 1n the end face thereof and a passage in the bearing member 17 is arranged to register therewith. Since the locking grooves 18 of the bearing member 17 which cooperate with the connecting bolts 8, make two positions of member 17 permissible when the latter is assembled on the drilling machine, two passages 20 are provided, as indicated in Fig. 2 in the same angular position in relation to the grooves 18, so that one of these passages must register with passage 19 in either position of the member. The motive fluid thus directed into the front head and pocketed therewithin finds its way along the ore of the head 7, not only keeping the latter-clear of detritus but also serving to a blow the same away from the drilling ma- The modification shown in Figs. 3 and 4 and diagrammatically in Fig. 5 not only includes all the features of the invention described abovein relation to Figs. 1 and 2 but also other important features. In Fig. 3 the drilling machine is shown provided with a front head 7 having therein a removable and renewable bushing 21 for the shank of the drill bit 14. For convenience and economy in making both the head and the bushing, the bore of the head is made circular and the exterior of the bushing conforms thereto. By changing bushing 21 the front head is readily adapted to take different slzes and shapes of drill steels. The bushing has an enlarged head 21' which is recelved m a counterbore 7 in the rear end 9f the front head thereby to retain the bushmg and fix its position within head 7".

. In stoping'drills, towhich the present in-' vention 1s particularly applicable, rotation of the (l7lll steel when necessary is accomphshed manually by rotating the entire drillmg machlne. Hence, the bushing 21 which rece ves the polygonal shank of the drill steel must be keyed ,to the drilling machine. 1s 1s preferably accomplished by forming the bushing 21 and the bearing member 17" W1th cooperating portions or lugs 21 and 17 respectlvely whic interlock or mesh when these parts are in assembled position. Since the bearing member 17" is already disposed 1n fixed relation relative to the drilling machine by the grooves 18 and connecting bolts 8, the construction just described serves securely to key the drill steel 14 to the drillmg machine for rotation therewith. In

tween the bushing 21 and the bore of the head 7'. The invention further contem lates mixing lubricant withthe motive flui 'con- I tinuously passing through passages 19 and 20 in any known or desired manner to further reduce the wear of the engaging ligartswithin the front head and to .assist in eeping out the detritus.

From the above it will be apparent that both the plain form of front head shown in Fig. 4 and the hushed form shown in Fig. 1

are adapted for use for both wet and dry drilling, inasmuch as the contlnuous stream of motive fluid admitted to the front head operates to keep detritus whether wet or dr out of the front head, that the life of ront head parts on machines provided with this arrangement will be greatly prolonged due to the decrease of vear of the same particularly when the contlnuous stream of motive fluid carries lubr1- cant with it, that both forms are arr'an ed effectively to key the drill steel to the (ll'llling machine for rotation therewith, and that this rotation arrangement 'is secured even when renewable bushings exteriorly cylindrical in form are utilized by reason of the interlocked construction of such bushings'with the front guide or closure member or other suitable part of the drilling machine. a

I claim as my invention:

1. The combination with a drilling machine of-the percussive type having a movable impact element, a bearing or guide member therefor keyed to said machine, a front head, a cylindrical bushing within said head receiving the shank of the drill steel, and co-operating parts on said bushing. and member for keying said bushing through said member to the machine.

2. The combination with a drilling machine of' the percusive type having a movable impact e ement, a front head, a bearing or guide member for said element interpose between said head and said machine and keyed to the latter, and a cylindrical bushing within said head, said bushing and said member being interlocked whereby rotation of the machine is transmitted throu b said member and said bushing to the dri 1 steel.

3. The combination with a drilling machine of the rcussive type having a movable impact e ement, a front head, a bearlng or guide member for said element interpose between said head and said machine and keyed to the latter, and a -cylindrical bushing within said head, said bushing and said member being disposed in endwise engagement and having complementary interlocking projections whereby rotation of the machine is transmitted through said member and said bushing to the drill steel.

4. The combination with a drilling machine of the percussive type having a movable im act element, a front head, a bearing or guidb member for said element interosed between said head and said machine,

olts uniting said head and machine and fitting in grooves in said member, a cylindrical bushing, within said head serving as a chuck for the drill steel, said bushing and said member being in endwise engagement and having complementary interlocking rojections whereby rotation of the drillmg lmachine will effect rotation of the drill stee 5. The combination with a drilling machine of the percussive type, of a front head therefor, a cylindrical bushin within said head serving as a chuck for tie drill steel, means independent of said head for keying said bushing to said machine for rotation therewith, and fluid pressure means for ,maintainin said bushing and the interior of said head ree of detritus to prevent excessive wear of the same.

6. The combination with a drilling machine of the percussive type, of a front head therefor, a cylindrical bushin within said head serving as a chuck for 51c drill steel, means independent of said head for keying said bushing to said machine for rotation therewith, and means for continuously admitting fluid pressure in limited amount to the interior of said head and to the bore of said bushing to keep out detritus thereby to prevent excessive wear.

7. The combination with the cylinder of drilling machine of the percussive type having a movable im act element, a front head, a: guide member or said element interposed between said head and said cylinder and keyed to the latter, a cylindrical bushing within said head serving as a chuck for the drill steel, cooperating parts on said member and said bushin keying the same together, said cylinder liaving a pressure fluid passage terminating adjacent said-member, and said member having a passage therethrough arranged to register with said pressure fluid passage to admit pressure fluid to the interior of said head and to the bore of said bushing to keep out detritus.

8. The combination with the cylinder of .a drilling machine of the percussive type having a movable impact element, a front head, a hearing or guide member for said element interposed between said head and said cylinder, bolts securing said head to said cylinder and fittin in grooves in said member, a cylindrical ushing within said head serving as a chuck for the drill steel, said bushing and said member being in endwise enga ement and having com' lementary inter ocking projections rovi ing' a clearance between the same, sai cylinder having a pressure fluid passage termmating adjacent said member, said member having a plurality of passages therethrough similarly disposed relative to the bolt grooves therein to dispose one of the passages in register with said pressure fluid assage in any permissible position of sai member relative to the cylinder, thereby to admit pressure fluid within said head and within and around said bushing to prevent the entrance of detritus.

Signed by me at Detroit, Mich., this 25th day of September, 1924.

ERNEST PENBERTHY. 

